Griddles are a major cooking appliance in commercial kitchens, particularly fast food and full-service chain restaurants. Typical prior art griddles are powered by either gas or electricity and typically have one heating element, one thermocouple and one thermostat per linear foot to permit wide temperature variations between heating elements. Power is literally pushed into the food.
The problems with the prior art griddles are numerous. Such griddles typically have a 70.degree. F. temperature variation across their surfaces. Further, they cannot deliver power to specific incremental areas. Thus, cold areas may call for heat, resulting in hot areas becoming overheated, or vice versa. The heat-up time from the point of turn-on is typically 20 minutes, and the griddles have a slow response time to changes in temperatures caused by a change of load. Such griddles are difficult to clean since the relatively large surface areas cannot be removed for cleaning. Further, conventional griddles do not provide cooking temperatures within three inches of their peripheries.
There are also prior art consumer oriented induction cooking stoves with special pots. For example, French Patent No. 2,527,916 discloses a pot or pan with a ferromagnetic bottom. Several different pots can be provided with a ferromagnetic bottom of different Curie temperatures whereby different cooking temperatures can be achieved. The pots have ferromagnetic bottoms, and the stove has induction coils. These devices have coils that do not provide uniform temperature across the bottom of the pot or pan and provide minimum shielding of RF radiation. Such coils are not designed for use in plate technology or for large size pots.